1. Field
The invention is in the field of machines and methods for separating usually unwanted components, such as pieces of bone, heavy connective tissue, and skin, or the pits, stems, and seeds of various fruits and berries, from the desired flesh of various composite materials, such as the relatively soft flesh of red meats, poultry, and fish, or the flesh of various fruits, berries, vegetables, and other food items.
2. State of the Art
In the processing of various kinds of meat for food, machines have been developed for a variety of purposes. A primary concern in such processing has been to leave in the meat as little as possible of relatively hard, inedible components, such as pieces or particles of bone, heavy connective tissue, and skin, as in the processing of chunks cut from carcasses of various animals for grinding into hamburger meat or the like, or in the processing of skeletal remains of poultry, especially chicken or turkey, to recover the small amount of flesh remaining attached to the skeletal bones following removal of as much of the flesh as possible by cutting and stripping from the bone.
A type of grinding machine that is widely used throughout the world in the production of hamburger meat, comprises a perforate screening plate of flat and usually disc formation usually having a rotary knife operable at and over the entry face thereof into which the meat material is fed. A flow channel may extend across the entry face of such a screening plate for collecting bones and other relatively hard matter as pushed across such entry face by the rotating knife, which not only scrapes the bone and other relatively hard matter from the entry face of the screening plate toward discharge therefor but also tends to push flesh through the screen openings, see Speco, Inc.'s Charles W. Hess U.S. Pat. No. 4,004,742 of Jan. 25, 1977.
Other machines widely used for processing skeletal remains of poultry, especially chicken, are known as "deboning" machines in accordance with Beehive Machinery, Inc.'s Archie R. McFarland U.S. Pat. No. 3,739,994 of Jun. 19, 1973, as reissued on Jul. 17, 1984 as Re. 31,631, the Claudio dos Santos U.S. Pat. No. 4,189,104 of Feb. 19, 1980, and the McFarland et al. U.S. Pat. No. 4,340,994 of Jul. 27, 1982, U.S. Pat. No. 4,480,980 of Nov. 6, 1984, and U.S. Pat. No. 4,566,640 of Jan. 28, 1986.
A later machine developed by Archie R. McFarland for Diamond Stainless Corporation of Salt Lake City, Utah, is disclosed in U.S. Pat. No. 5,580,305 of Dec. 3, 1996 for "Segregating Meat from Bone, Heavy Tissue, and Skin". This machine operates primarily on chunks of cut meat that include sizeable pieces of bone and often heavy connective tissue and skin.
Although the early deboning machines provide for the build-up of a so-called "filter mat" across the inner face of a tubular screen through which the feed material is advanced by a conveyor screw for filtering out small particles of bone from the flesh about to pass through the screen, the McFarland machine of U.S. Pat. No. 5,580,305 is not concerned with such a filter mat. Rather it increases production of the relatively soft product while effectively dealing with relatively large pieces of bone usually contained by the chunks of cut meat. There, a conveying cutter helical screw or auger is provided in close cutting relationship with the perforations of the usual cylindrically tubular screen in combination with a bone-cutting ring valve at the discharge end of such screen, which provides advantageous back pressure within the tubular screen as does the ring valve of a usual deboning machine.
An older McFarland U.S. patent assigned to Beehive Machinery, Inc. is U.S. Pat. No. 3,825,231 of Jul. 23, 1974 entitled "Twin Screw Continuous Processing Machine". It discloses twin helical screws at the bottom of a hopper for mixing meat materials in the hopper and for discharging the mixed material into the entry face of a flat disc grinder screen, with anything that does not pass through the screen falling back into one of the screws for transfer to the other screw for further mixing.
There are two additional prior art patents, one U.S. Pat. No. 5,443,214 of Aug. 22, 1995, inventor Nick J. Lesar, entitled "Hard Material Collector Assembly for a Grinder", and issued to Assignee Weiler and Company, Inc. of Whitewater, Wis., cites both the previously mentioned McFarland U.S. Pat. No. 3,739,934 and Hess U.S. Pat. No. 4,004,742; the other one is U.S. Pat. No. 5,452,650 of Sep. 26, 1995 for "Juice Extractor" issued to Korean inventor Mun-Hynn Lee.